英文:
Spring data jpa creates wrong fields in empty database for entity with composite primary key that contains foreign key
问题
以下是翻译好的部分：
我有以下数据库结构以进行简化：
表 Product：
id（主键）
表 Place：
id（主键）
表 WarehouseProduct：
place（主键，外键）
product（主键，外键）
count
我使用以下代码来描述代码中的数据库：
Place：
@Entity
public class Place {
@Id
String id;
}
Product：
@Entity
public class Product {
@Id
String id;
}
WarehouseProduct 的主键：
@Embeddable
public class WarehouseProductPK implements Serializable {
String place;
String product;
}
WarehouseProduct：
@Entity
public class WarehouseProduct {
@EmbeddedId;
WarehouseProductPK pk;
@OneToOne(targetEntity = Product.class)
Product product;
@OneToOne(targetEntity = Place.class)
Place place;
@Column(nullable = false)
int count;
}
我在空的 h2 数据库上进行了测试。结果是为 WarehouseProduct 创建了以下表格：
表 WarehouseProduct：
place（主键）
product（主键）
count
placeId（外键）
productId（外键）
如何使用 Spring Data JPA 在空数据库中创建所需的数据库结构？
英文:
I have following database structure to simplify:
Table Product:
-----
id(pk)
Table Place:
-----
id(pk)
Table WarehouseProduct:
-----
place(pk, fk)
product(pk, fk)
count
And i use this code to describe database in code:
Place:
@Entity
public class Place {
@Id
String id;
}
Product:
@Entity
public class Product {
@Id
String id;
}
primary key for WarehouseProduct:
@Embeddable
public class WarehouseProductPK implements Serializable {
String place;
String product;
}
WarehouseProduct:
@Entity
public class WarehouseProduct {
@EmbeddedId;
WarehouseProductPK pk;
@OneToOne(targetEntity = Product.class)
Product product;
@OneToOne(targetEntity = Place.class)
Place place;
@Column(nullable = false)
int count;
}
I test this on empty h2 database. In result is created following table for WarehouseProduct:
Table WarehouseProduct:
-----
place(pk)
product(pk)
count
placeId(fk)
productId(fk)
How to create required db structure with data jpa in empty database?
答案1
得分: 0
使用以下代码为 WarehouseProduct 实体数据，JPA 将创建所需的数据库结构：
WarehouseProduct 的主键：
@Embeddable
public class WarehouseProductPK implements Serializable {
@OneToOne(targetEntity = Place.class)
Place place;
@OneToOne(targetEntity = Product.class)
Product product;
}
WarehouseProduct：
@Entity
public class WarehouseProduct {
@EmbeddedId;
WarehouseProductPK pk;
@Column(nullable = false)
int count;
}
结果是在空的 H2 数据库中，我得到了如下的 WarehouseProduct 表格：
Table WarehouseProduct:
-----
placeId(pk, fk)
productId(pk, fk)
count
英文:
With following code for WarehouseProduct entity data jpa creates required database structure:
Primary key for WarehouseProduct:
@Embeddable
public class WarehouseProductPK implements Serializable {
@OneToOne(targetEntity = Place.class)
Place place;
@OneToOne(targetEntity = Product.class)
Product product;
}
WarehouseProduct:
@Entity
public class WarehouseProduct {
@EmbeddedId;
WarehouseProductPK pk;
@Column(nullable = false)
int count;
}
In result i got such table for WarehouseProduct in empty h2 db:
Table WarehouseProduct:
-----
placeId(pk, fk)
productId(pk, fk)
count
答案2
得分: 0
@Embeddable
public class WarehouseProductPK implements Serializable {
@Column(name="place")
String placeId;
@Column(name="product")
String productId;
}
@Entity
public class WarehouseProduct {
@EmbeddedId
WarehouseProductPK pk;
@OneToOne
@MapsId("placeId")
@JoinColumn(name="place")
Place place;
@OneToOne
@MapsId("productId")
@JoinColumn(name="product")
Product product;
@Column(nullable = false)
int count;
}
英文:
@Embeddable
public class WarehouseProductPK implements Serializable {
@Column(name="place")
String placeId;
@Column(name="product")
String productId;
}
@Entity
public class WarehouseProduct {
@EmbeddedId;
WarehouseProductPK pk;
@OneToOne
@MapsId("placeId")
@JoinColumn(name="place")
Place place;
@OneToOne
@MapsId("productId")
@JoinColumn(name="product")
Product product;
@Column(nullable = false)
int count;
}
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